Cellulosic fibrous webs such as paper are well known in the art. Such fibrous webs are in common use today for paper towels, toilet tissue, facial tissue, napkins and the like. The large demand for such cellulosic fibrous web products has created a demand for improved versions of the products and the methods of their manufacture.
In order to meet the needs of the consumer, cellulosic fibrous webs must exhibit several characteristics. They must have sufficient tensile strength to prevent the structures from tearing or shredding during ordinary use or when relatively small tensile forces are applied. The cellulosic fibrous webs must be absorbent, so that liquids may be quickly absorbed and fully retained by the fibrous structure. Also, the web should exhibit softness, so that it is tactilely pleasant and not harsh during use.
Caliper is the apparent thickness of a cellulosic fibrous web measured under a certain mechanical pressure and is a function of basis weight and web structure. Strength, absorbency, and softness are influenced by the caliper of the cellulosic fibrous web.
Processes for the manufacturing of paper products generally involve the preparation of an aqueous slurry of cellulosic fibers and subsequent removal of water from the slurry while contemporaneously rearranging the fibers to form an embryonic web. After the initial forming, the fibrous web is carried through a drying process on another fabric referred to as the drying fabric which is in the form of an endless belt. During the drying process, the embryonic web may take on a specific pattern or shape caused by the arrangement and deflection of cellulosic fibers.
U.S. Pat. No. 4,529,480 issued to Trokhan on Jul. 16, 1985 introduced a web-making belt comprising a foraminous woven member which was joined to a hardened photosensitive resin framework. The resin framework was provided with a plurality of discrete, isolated channels known as deflection conduits. The utilization of the belt in the web-making process provided the possibility of creating fibrous web having certain desired characteristics of strength, absorption, and softness. Generally speaking, the webs produced with these web-making belts are characterized by having a high density knuckle region corresponding to the framework, and a plurality of relatively low density pillow regions or domes corresponding to the deflection conduits.
Once the drying phase of the web-making process is finished, the arrangement and deflection of fibers is complete. However, depending on the type of the finished product, fibrous web may go through additional processes such as calendering, softener application, and converting. These processes tend to compress the dome regions of the fibrous web and reduce the caliper. Thus, producing high caliper finished fibrous web products requires forming cellulosic fibrous structures having a resistance to compressive forces.
Accordingly, the present invention provides a web-making fabric that enables the formation of a high caliper fibrous structure that is resistant to compressive forces